Silento, the Atlanta rapper known for the hit single and viral dance “Watch Me (Whip/Nae Nae),” was arrested and charged with murder in the shooting death of his cousin, authorities said.The 23-year-old, whose real name is Ricky Lamar Hawk, was arrested Monday after police investigated the death of his 34-year-old cousin, Frederick Rooks, according to a statement from the DeKalb County Police Department.Police responded to